The Arizona Constitution was adopted in the afternoon of Dec. 9, 1910. The Constitutional Convention lasted 61 days with 52 delegates representing the people of Arizona in attendance. Forty of the delegates voted approval, while 12 voiced opposition to its provisions, chiefly those that established the Initiative, Referendum and Recall. Nevertheless, one of the members voting "no" appended his signature to the document. The constitution then went to the vote of the people the next February for ratification. Formulation of the Constitution was authorized by an Enabling Act of Congress that received the President's signature on June 20, 1910, after a historic struggle waged by the people of Arizona over more than a quarter of a century, for the right of local self-government and Arizona's recognition as a member of the Union of States.